Generally, an Electronic Service Guide (ESG) enables a terminal to communicate what services are available to end users and how the services may be accessed. ESG fragments are independently existing pieces of the ESG. Traditionally, ESG fragments comprise XML documents, but more recently they have encompassed a vast array of items, such as for example, a SDP (Session Description Protocol) description, textual file, or an image. The ESG fragments describe one or several aspects of currently available (or future) service or broadcast program. Such aspects may include for example: free text description, schedule, geographical availability, price, purchase method, genre, and supplementary information such as preview images or clips. Audio, video and other types of data comprising the ESG fragments may be transmitted through a variety of types of networks according to many different protocols. For example, data can be transmitted through a collection of networks usually referred to as the “Internet” using protocols of the Internet protocol suite, such as Internet Protocol (IP) and User Datagram Protocol (UDP). Data is often transmitted through the Internet addressed to a single user. It can, however, be addressed to a group of users, commonly known as multicasting. In the case in which the data is addressed to all users it is called broadcasting.
One way of broadcasting data is to use an IP datacasting (IPDC) network. IPDC is a combination of digital broadcast and Internet Protocol. Through such an IP-based broadcasting network, one or more service providers can supply different types of IP services including on-line newspapers, radio, and television. These IP services are organized into one or more media streams in the form of audio, video and/or other types of data. To determine when and where these streams occur, users refer to an electronic service guide (ESG). One example used in digital video broadcasting (DVB) streams is an electronic program guide (EPG). One type of DVB is Digital video broadcasting-handheld (DVB-H), a recently developed technology that increases the capabilities and services available on small handheld devices, such as mobile telephones. The DVB-H is designed to deliver 10 Mbps of data to a battery-powered terminal device.
DVB transport streams deliver compressed audio and video and data to a user via third party delivery networks. Moving Picture Expert Group (MPEG) is a technology by which encoded video, audio, and data within a single program is multiplexed, with other programs, into a transport stream (TS). The TS is a packetised data stream, with fixed length packets, including a header. The individual elements of a program, audio and video, are each carried within packets having a unique packet identification (PID). To enable a receiver device to locate the different elements of a particular program within the TS, Program Specific Information (PSI), which is embedded into the TS, is supplied. In addition, additional Service Information (SI), a set of tables adhering to the MPEG private section syntax, is incorporated into the TS. This enables a receiver device to correctly process the data contained within the TS.
The present invention, however, is also is applicable to other traditional digital mobile broadcast systems such as, for example, T-DAB, DMB (including T/S-DMB, T-DMB, and DMB-T), ISDB-T, ATSC, MediaFlow, and non-traditional systems such 3GPP MBMS (Multimedia Broadcast/Multicast Services) and 3GPP2 BCMCS (Broadcast/Multicast Service).
As image and other large files predominate the ESG transport, there exists a need to efficiently transport the ESG fragments across the desired networks to the end receivers. Previous systems transmitted a header before the ESG, however, this is quite inefficient because if containers carrying ESGs are transmitted before the header, the information is inaccessible until the header arrives and there is the risk of not receiving the header, thereby rendering the information in the container useless. Current attempts focus on associating several fragments together; however, these attempts have been largely unsuccessful due to the lack of unique identification of the fragments, an efficient header or indexing structure, or requiring the presence of repetitive parameters.
As stated above, the ESG fragments may be transported by IPDC over a network, such as for example, DVB-H to destination devices. The destination device must then again determine the ordering of the ESG fragments and assemble them into useful information. The prior art methods of receiving, organizing, and implementing the ESG fragments has a great impact on mobile device performance and battery lifetime. Furthermore, in order to keep server side and client side ESG fragments in synch, any change in content of ESG fragments needs to be indicated. Additionally, any change in how ESG fragments are distributed across carousels requires the client side to verify if all the fragments are still available and valid in any new distribution set up and if their content has not changed. A result of current systems and proposals is the unnecessary re-distribution of unchanged ESG fragments along with the updated fragments. Lastly, there is not a protocol for prioritizing the ESG fragments to ensure the end user of a destination device receives more pertinent ESG data in a timely manner.
It goes from the forgoing, therefore, there exists a need in the art to minimize the number of updates required on a client side or destination device caused by the re-distribution of the “unchanged” ESG fragments into different carousels. There also appears to be a need to prioritize the ESG fragments and implement a system to ensure the most important ESG fragments are delivered in a timely manner.